Signalis is stupendously well-reviewed. I'm less convinced, and am writing halfway thoughts on the knowledge there's a 50% chance I won't see the finish.
Aesthetically born from the era of CRT televisions, analogue error codes, and fifth-generation video game consoles. Narratively created via H.P. Lovecraft, Stanley Kubrick, David Lynch, and plenty more I didn't pick up on.
Visually you will feel very at home here if you're familiar with analogue horror. PS1-era graphics and icons help this along, to the extent that you can see the direct inspiration from specific games - Metal Gear Solid comes to mind for some of the more subtle instances.
Sound design is quite neat. I'm a big fan of the subtle touch, and there's enough audio cues to nudge the player into uncertainty without coming off as in-your-face.
Mechanics is where the game falls down quite hard. It pulls far too enthusiastically from the old Resident Evil games - you get a key that forces you to backtack two levels, which lets you unlock a safe that gives you a key, which makes you traverse one floor in order to open a door leading to a desk that contains a key, which opens a lift on a different floor that leads to... another key. Utterly obnoxious.
Heavily limiting the player's inventory would be fine, except for the occasional room contiaining 2-3 key items, forcing you to backtrack multiple floors to the single storage point available to you.
Puzzles are fine, combat is fine, but the above drags the game to a state where I simply don't care to carry on. The plot is working towards something interesting, but the interest simply isn't there any more. There's nothing wrong with a slightly shorter game.